I Can't able to connect QMYSQL Driver in QT Creator 4.9.2 and QT 5.12.4

RonaldViscarraL

Hi, in most of linux distros, there's not mysql, but mariadb, if this is the case, then you need to make a soft link to mariadb lib and call it like the mysql required

Surendar Dharani

@ronaldviscarral Hi,

Thank you very much. Please tell me how to do it by step by step. Because i'm new in this. Thanks in advance.

RonaldViscarraL

@surendar-dharani sure, first, install mariadb in your linux distro, then as super user in a terminal (for a x64 base system):

ln -s /usr/lib64/libmariadb.so.3 /usr/lib64/libmysqlclient.so.18

you should adapt it to your distro paths and mariadb version

Surendar Dharani

@ronaldviscarral said in I Can't able to connect QMYSQL Driver in QT Creator 4.9.2 and QT 5.12.4:

ln -s /usr/lib64/libmariadb.so.3 /usr/lib64/libmysqlclient.so.18

Hi,

I have uninstalled by using following commands and installed maria DB.

sudo apt-get remove --purge mysql-server mysql-client mysql-common

installed mariadb by follwing command,
sudo apt-get install mariadb-server

And tried to compile same driver not laoded in mysql

QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7

Now what to i do?

SGaist

Start your application with the QT_DEBUG_PLUGINS environment variable set to 1.

You'll see what is happening with your plugin.

RonaldViscarraL

@surendar-dharani Your OS seems to have mysql, so, better install them.

If you didn't compile the mysql driver, you could guide you with:
https://fecub.wordpress.com/2014/08/12/compilecreate-mysql-driver-for-qt5-on-windows/

When you build an app that's use mysql driver, and the plugin is compiled, and there's no mysql library availible in your system, you have the error:

QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QODBC QODBC3 QPSQL QPSQL7

notice that QMYSQL is availible but not loaded, means that the plugin is compiled but the library was not found it.

so, having been installed mysql-server and mysql-client from your package manager, find the library libmysqlclient.so.18, in a terminal you could use as super user:

find / -name libmysqlclient.so.18

paste here the results to check it out

Surendar Dharani

@ronaldviscarral @SGaist Hi have installed in my other system from the scratch itself, Now i got this.

When i ran this sh configure -sql-mysql

Output:

Qt Sql Drivers:
DB2 (IBM) .............................. no
InterBase .............................. no
MySql .................................. yes
OCI (Oracle) ........................... no
ODBC ................................... no
PostgreSQL ............................. no
SQLite2 ................................ no
SQLite ................................. yes
Using system provided SQLite ......... no
TDS (Sybase) ........................... no

And i tried to run QT 5.13.1

And I got this ,

QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QODBC QODBC3 QPSQL QPSQL7

And I checked in /opt/Qt/5.13.1/gcc_64/plugins/sqldrivers/

But libqsqlmysql.so file is not found in this location.

i think little thing is missing here. Please guide me. Thanks in advance.

Quang Phu

Hi @Surendar-Dharani ,
you have to install QMYSQL plugin first.
I met this issue before and have 2 topics that you can refer
https://forum.qt.io/topic/106421/qt-mac-version-doesn-t-have-file-libqsqlmysql-dylib
https://forum.qt.io/topic/106565/mysql-qt-create-plugin-mysql-for-qt-on-mac

Surendar Dharani

@quang-phu @SGaist @RonaldViscarraL

when i run this /opt/Qt/5.13.1/Src/qtbase/src/plugins/sqldrivers# make sub-mysql

I got this :
cd mysql/ && ( test -e Makefile || /usr/lib/qt5/bin/qmake -o Makefile /opt/Qt/5.13.1/Src/qtbase/src/plugins/sqldrivers/mysql/mysql.pro MYSQL_PREFIX=/usr/local ) && make -f Makefile
make[1]: Entering directory '/opt/Qt/5.13.1/Src/qtbase/src/plugins/sqldrivers/mysql'
g++ -c -g -O2 -fdebug-prefix-map=/build/qtbase-opensource-src-5DihdB/qtbase-opensource-src-5.9.5+dfsg=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -O2 -std=c++1z -fvisibility=hidden -fvisibility-inlines-hidden -fno-exceptions -Wall -W -Wvla -Wdate-time -Wshift-overflow=2 -Wduplicated-cond -Wno-stringop-overflow -D_REENTRANT -fPIC -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_NO_CAST_TO_ASCII -DQT_NO_CAST_FROM_ASCII -DQT_NO_EXCEPTIONS -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -DQT_NO_DEBUG -DQT_PLUGIN -DQT_SQL_LIB -DQT_CORE_LIB -I. -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql/5.9.5 -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql/5.9.5/QtSql -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore/5.9.5 -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore/5.9.5/QtCore -isystem /usr/include/x86_64-linux-gnu/qt5 -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore -I.moc -isystem /usr/include/mysql -I/usr/lib/x86_64-linux-gnu/qt5/mkspecs/linux-g++ -o .obj/qsql_mysql.o qsql_mysql.cpp
In file included from /usr/include/x86_64-linux-gnu/qt5/QtSql/qtsqlglobal.h:43:0,
from /usr/include/x86_64-linux-gnu/qt5/QtSql/qsqldriver.h:43,
from qsql_mysql_p.h:54,
from qsql_mysql.cpp:40:
qsql_mysql.cpp:1469:5: error: division by zero in #if
#if QT_CONFIG(thread)
^
qsql_mysql.cpp:1483:5: error: division by zero in #if
#if QT_CONFIG(thread)
^
qsql_mysql.cpp: In function ‘QSqlField qToField(MYSQL_FIELD, QTextCodec)’:
qsql_mysql.cpp:344:44: error: no matching function for call to ‘QSqlField::QSqlField(QString, QVariant::Type, QString)’
toUnicode(tc, field->table));
^
In file included from qsql_mysql.cpp:46:0:
/usr/include/x86_64-linux-gnu/qt5/QtSql/qsqlfield.h:60:5: note: candidate: QSqlField::QSqlField(const QSqlField&)
QSqlField(const QSqlField& other);
^~~~~~~~~
/usr/include/x86_64-linux-gnu/qt5/QtSql/qsqlfield.h:60:5: note: candidate expects 1 argument, 3 provided
/usr/include/x86_64-linux-gnu/qt5/QtSql/qsqlfield.h:57:14: note: candidate: QSqlField::QSqlField(const QString&, QVariant::Type)
explicit QSqlField(const QString& fieldName = QString(),
^~~~~~~~~
/usr/include/x86_64-linux-gnu/qt5/QtSql/qsqlfield.h:57:14: note: candidate expects 2 arguments, 3 provided
Makefile:376: recipe for target '.obj/qsql_mysql.o' failed
make[1]: [.obj/qsql_mysql.o] Error 1
make[1]: Leaving directory '/opt/Qt/5.13.1/Src/qtbase/src/plugins/sqldrivers/mysql'
Makefile:42: recipe for target 'sub-mysql' failed
make: [sub-mysql] Error 2**

and when i ran sh configure in qtbase folder i got this,

g++: error: /opt/Qt/5.13.1/Src/qtbase/lib/libqtpcre2.a: No such file or directory
Makefile:1214: recipe for target '../../lib/libQt5Core.so.5.13.1' failed
make[2]: *** [../../lib/libQt5Core.so.5.13.1] Error 1
make[2]: Leaving directory '/opt/Qt/5.13.1/Src/qtbase/src/corelib'
Makefile:213: recipe for target 'sub-corelib-install_subtargets' failed
make[1]: *** [sub-corelib-install_subtargets] Error 2
make[1]: Leaving directory '/opt/Qt/5.13.1/Src/qtbase/src'
Makefile:62: recipe for target 'sub-src-install_subtargets' failed
make: *** [sub-src-install_subtargets] Error 2

SGaist

From the looks of it, you are mixing several versions of Qt.
There's references to both Qt 5.13 and Qt 5.9.5 which is not a good sign.

Surendar Dharani

@sgaist hi,

How to do it for version 5.13.1

Because i got confused. Now what I have to do?

Uninstall 5.9 version and try qmakr for 5.13.1 version?

Surendar Dharani

Hi,

I got output.

In terminal,

I just ran sh configure -sql-mysql
after that ran make
after that ran make install

Thanks for your valuable support and valuable time.